Come to Cube and you have a highly efficient threat that plays well with the various 1-drop mana dorks that often fill greens slots and has a strong mana sink to ensure you can use every bit of mana you generate
Then each player on each other team in turn order does the same
Most players dont encounter grading until the first time they come into ownership of a collectible worth preserving
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of The Wind Crystal's first ability)
While it does also give that opponent another turn after (so not quite a Mindslaver), it can still be enough
You pay the cost, discard that card, then can search your library for a card with the same mana value as the card you discard